Deflecting catheters, also referred to as steerable catheters are used in a variety of medical and non-medical procedures. In diagnostic and therapeutic medical procedures, a steerable catheter provides an operator (e.g., physician) with the ability to articulate the distal tip of the catheter in order to travel through constrained and/or tortuous anatomy, and/or to direct the distal catheter tip in a particular direction. Similar mechanisms are used in medical and nonmedical endoscopes to steer them to a target site and to orient a device portion (e.g., including a camera or other visualization means) in a desired direction.
In a typical design, control wires are manipulably attached at a proximal end of the device, and also attached at or near a distal end of the device. Such a configuration operates by manipulating one or more of the control wires to increase and/or decrease a generally longitudinal force on the distal device end that will deflect it in a desired direction. As described with reference to an existing steerable endoscopic camera device 50 of FIG. 1, the control wires may be actuated by rotation of control wheels 51, 53. Each control wheel can be rotated to operate a control wire or pair of control wires in a manner exerting push/pull tension on a deflectable distal device portion (not shown, but well-known in the art) to deflect that portion along a first plane, while the other control wheel operates similarly to deflect that portion along a second plane intersecting (e.g., orthogonal to) the first plane. At times, it is desirable to lock that distal device portion into a particular deflected orientation (e.g., so that the operator may execute another task requiring releasing hand contact with one or both control wheels). The illustrated device 50 includes a first brake for the first control wheel 51, with a twistable knob 55 for locking/unlocking an internal brake mechanism that operates along the central rotational axis of the first control wheel 51. The illustrated device 50 includes a second brake for the second control wheel 51, with a lever 57 for locking/unlocking an internal brake mechanism that operates by exerting a braking engagement along the central rotational axis of the second control wheel 53. One or both brake controls 55, 57 require a user to change his/her grip for actuation. Other examples of brake mechanisms are described and illustrated in, for example, U.S. Pat. Nos. 8,864,656; 8,808,168; 8,608,649; 8,641,604; 8,366,604; 6,673,012; and 5,507,717.
It is be desirable to provide braking means that allow a user to “lock” into place the wire-operating elements within the control handle in a manner that will hold the distal end of the steerable catheter in a user-determined deflected or non-deflected orientation. Moreover, there is a need for such a braking means that is operable without a user needing to release other control elements of the steerable catheter, and which may simultaneously brake or even lock more than one control wheel/wire element to as to control (that is reduce or eliminate) deflection of the distal end portion through/along all planes.